It's good for what it is, but it's not especially warm.
1. About as warm as 2mm or so neoprene;
2. Doesn't crush over time, so no reduction in insulation ability as it ages;
3. Potentially much easier to doff/don, especially when wet (I only use a long sleeve top w/o hood, though, and a full suit may be just as much of a PITA as a thin wet suit);
4. Almost no inherent buoyancy...there's some, but it's only enough to make soaking all of it at once a bit tricky, not enough to matter re: weighting/trim.
5. Less bulky/restrictive underwater -- I usually dive in just the Lavacore top and some Irikonji trunks, and moving around is very easy. A bit easier than my old, well-crushed 3mm Pinnacle ME suit and a lot easier than my 7mm ME suit or Fusion Bullet.
6. One garment, multiple uses: I've found the longsleeve top w/o hood to be just what I needed for a tropical undergarment in my drysuit for dives where the deco hang is just too many hours for diving wet. I need to buy some Lavacore socks to make sliding through the Fusion legs easier and keep my toes warmer.
Durability seems decent. I have some fuzzing around the shoulders from my harness, but everything else is holding up pretty well, even the logos. It's basically a glorified rashguard with a heavy fleece lining and works great as long as you don't need to stay too warm.